JPS6024844B2 - Manufacturing method of high strength, high Young's modulus polyester fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing high strength, high Young's modulus polyester fibers from a specific polyester polymer that exhibits optical anisotropy when melted.

BACKGROUND OF THE INVENTION Conventionally, polyethylene terephthalate fibers have excellent mechanical strength, heat resistance, and chemical resistance, and are therefore widely used in clothing and industrial applications.

However, in industrial applications such as tire cords, which require particularly high strength and Young's modulus, performance is still not sufficient. On the other hand, aromatic polyamide fibers made of polyP-phenylene phthalamide, polyP-penzamide, etc. are known as fibers having extremely high strength and Young's modulus. However, these polyamides
While polyethylene terephthalate and the like can be easily made into fibers by melt drawing, it is generally difficult to produce fibers without using dry paper yarn or wet spinning, and there are many industrial disadvantages such as solvent recovery. As a result of intensive studies to obtain fibers that can be made into melt-grade yarns and have high strength and Young's modulus, the present inventors have previously discovered oxybenzoic acid residue A, aromatic dihydroxy compound (dioxyhensen) base B, and carbonate base. C
A fiber mainly composed of polyester, the fiber has an intrinsic viscosity of 0.3 or more and a tensile strength of acid/
A polyester fiber characterized by having a de of more than 2000k9/de and a Young's modulus of more than 2000 k9/g, and an oxybenzoic acid residue A, an aromatic dihydroxy compound (dioxybenzene) residue B, a carbonic acid residue C, and an aromatic dicarbonate. A fiber made of polyester mainly composed of acid residues D, characterized in that the fiber has an intrinsic viscosity of 0.3 or more, a tensile strength of Sat/de or more, and a Young's modulus of 2000K9/ or more. We proposed polyester fiber. (Japanese Patent Publication No. 59-45763) Conventionally, polymers such as polyethylene terephthalate, nylon 6, nylon 6 box, etc. have a melt viscosity of at most 5000 poise in the form of paper yarn, and do not exhibit heterogeneity when melted. , there are relatively few troubles during melt spinning, and the land length L of the paper thread nozzle
The ratio L/D between this and Kongryu D is at most 3. Approximately 1.5 for fusuf
Among yarns with irregular cross sections, yarns with a diameter close to 1.0 are often used.

However, polyester polymers that exhibit anisotropy when melted as mentioned above are already highly oriented during spinning, and unlike general-purpose synthetic fibers (polyethylene terephthalate, nylon, etc.), they cannot be stretched or heat treated. is not necessarily required.

Therefore, in order to obtain fibers with high strength and high Young's modulus from these polymers, it is necessary to orient the polymer molecules in the fiber axis direction to a higher degree within the paper spinneret during spinning. Purpose of the Invention The purpose of the present invention is to produce polyester fibers with high strength and high Young's modulus through the spinning process alone by orienting the molecules of the polyester polymer more highly in the fiber axis direction within the spinneret during spinning. The purpose is to provide a method.

Structure of the Invention The inventors of the present invention have carefully studied the method for fixing the polymer by melting paper while keeping these points in mind. As a result, the ratio of the land length L of the spinneret nozzle to the hole diameter ○ [L/○] and the taper angle were determined. It was discovered that the desired high-performance fiber could be obtained by regulating the amount of carbon dioxide, and the present invention was achieved based on this finding.

That is, the present invention uses a polyester polymer (sometimes referred to as polyester carbonate) mainly composed of oxybenzoic acid residue A, aromatic dihydroxy compound residue B, and carbonate residue C as a land of a nozzle hole. Cho L and Koufeng D
The ratio L/D is 5 or more, and the taper angle is 50 to 130.
This is a method for producing high-strength, high-Young's-modulus fibers, which is characterized in that the fibers are melt-warped using a paper spinneret at ℃.

In the polyester polymer used in the method of the present invention,
Compounds that provide the oxybenzoic acid residue A are mainly p-oxybenzoic acid and m-oxybenzoic acid. It may also be a compound substituted with a halogen atom, an alkyl group, an alkoxy group, such as a chlorine atom, a bromine atom, an iodine atom, a methyl group, an ethyl group, a methoxy group, or an ethoxy group.

Examples of such nuclear-substituted compounds include 3-chloro-4
-oxybenzoic acid, 3-promu-4-oxybenzoic acid,
3-Methyl-4-oxybenzoic acid, 3-methoxy-4-
Oxybenzoic acid, 3,5-dichloro-4-oxybenzoic acid, 3,5-dichrome-4-oxybenzoic acid, 4-chloro-3-oxybenzoic acid, 4-methyl-3-oxybenzoic acid, 4-methoxy-3-oxybenzoic acid etc. can be mentioned. In the present invention, it is preferable that p-oxybenzoic acid or its nuclear substituted derivative accounts for 50 mol% or more, more preferably 70 mol% or more, of the compound that provides these oxybenzoic acid residues A.

, Incidentally, as an example of the compound giving the oxybenzoic acid residue A, taking p-oxybenzoic acid residues as an example, in addition to p-oxybenzoic acid, lower aliphatic carboxylic acid esters such as p-acetoxybenzoic acid, Aryl esters such as phenyl p-oxybenzoate and methyl p-oxybenzoate, lower alkyl esters, and acid chlorides such as p-oxybenzoic acid chloride can also be mentioned.

On the other hand, compounds that give aromatic dihydroxy compound residues B (for example, mainly include hydroquinone and resorcinol,
One or more of the hydrogen atoms in the aromatic nucleus of the aromatic dihydroxy compound is a halogen atom, an alkyl group, an alkoxy group, such as a chlorine atom, a bromine atom, an iodine atom, a methyl group,
It may also be a compound substituted with an ethyl group, a methoxy group, an ethoxy group, or the like.

Examples of such nuclear-substituted compounds include hydroquinone chloride, hydroquinone bromide, methylhydroquinone,
Examples include methoxynohydroquinone, resorcinol bromide, resorcinol chloride, methylresorcinol, and methoxyoresorcinol. In the present invention, it is preferable that 50 mol% or more, more preferably 70 mol%, of the compound providing these aromatic dihydroxy compound residues B be hydroquinone or its nuclear substituted product.

Among these, hydroquinone is particularly preferably used. In addition, taking hydroquinone residue as an example of the compound that provides the aromatic dihydroxy compound residue B, in addition to hydroquinone, p-diacetoxyhydroquinone p
Preferred examples include esters of lower aliphatic carboxylic acids such as -dibenzoyloxybenzene or aromatic carboxylic acids. Further, as the compound which provides the carbonic acid residue C 2 referred to in the present invention, there are mainly diaryl carbonates such as diphenyl carbonate, and halides such as phosgene.

The preferable copolymerization ratio of the oxybenzoic acid residue A, the aromatic dihydroxy compound residue B, and the carbonic acid residue C is as follows: MA is the number of moles of the oxybenzoic acid residue A, and the number of moles of the aromatic dihydroxy compound residue B is M old, the number of moles of carbonate residue C is MC
If so, 30/70 SMA/M old≦95/5, 30 no 70 SMA/MCS99/1, more preferably 4
0 no 60 SMA/M old ≦90/10, 40 no 60 SMA
/MC≦95 no 5.

In the present invention, a part of the oxybenzoic acid residue A, for example, 50 mol% or less, more preferably 30 mol% or less, is an aromatic oxycarboxylic acid such as oxynaphthoic acid, oxydiphenylcarboxylic acid, etc. It may be replaced with a residue of a group oxycarboxylic acid, or an aliphatic oxycarboxylic acid such as oxycaproic acid, or an alicyclic oxycarboxylic acid such as cyclohexaneoxycarboxylic acid.

Further, a part of the aromatic dihydroxy compound residue B, for example, 50 mol% or less, more preferably 30 mol% or less, may be replaced with other dihydroxy compounds, such as dioxydiphenyl, dioxynaphthalene, 2,2-bis(4-hydroxyphenyl), etc. Aromatic dihydroxy compounds such as enyl)propane, 1,1-pis(4-hydroxyphenyl)cyclohexane, and their nuclear substitution compounds, or aliphatic compounds such as ethylene glycol, neoberethylene glycol, cyclohexanediol, and cyclohexane dimethylol. It may be replaced with a residual alicyclic diol or the like. Furthermore, some of the carbonic acid residues C include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, methylterefuric acid, methylisophthalic acid, diphenoxychetadylcarboxylic acid, diphenyl etherdicarboxylic acid, diphenylsulfonic acid It may be replaced with a residue of aromatic dicarboxylic acid such as ponic acid. That is, the above polyester contains oxybenzoic acid residue A, aromatic dihydroxy compound residue B, and carbonic acid residue C.
However, it may further contain an aromatic dicarpone residue D as a fourth component.

In this case, compounds that give the aromatic dicarboxylic residue D (for example, Examples include sulfone dicarboxylic acid and diphenoxychetane dicarboxylic acid.

When the polyester contains aromatic dicarboxylic residue D as four components in addition to residues A to C, if the number of moles of each component is MA, Mold, MC, and MD, vote ≦Learn≦
It is preferable that the ratio satisfies 30 MC<MD.

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It takes volume C.

Further, the polyester composed of the residues A to C (and D) described above is produced, for example, by the following method.

That is, p-oxybenzoic acid, hydroquinone,
Diphenyl carbonate (and terephthalic acid) is polymerized in the melt or in the cold phase or in solution.

(b) Phenyl p-oxybenzoate or p-acetoxybenzoic acid, hydroquinone, diphenyl carbonate (and dimethyl terephthalate) are polymerized in a melt, solid phase, or solution.

p-oxybenzoic acid and diphenyl carbonate (and terephthalic acid) are added to polycarbonate of hahydride 0 quinone and polymerized in melt, solid phase or solution.

Z2 p-oxybenzoic acid chloride, hydroquinone, and phosgene (and terephthalic acid dichloride) are polymerized in an alkaline solution. The polyester can be easily obtained by methods such as the following.

Next, the polymerization methods (i) to (c) above for obtaining the polyester will be explained in more detail. The polymerization reaction temperature is generally not less than 18 degrees Celsius, preferably not less than 200 degrees Celsius, particularly not less than 250 degrees Celsius and not less than 40 degrees Celsius. The polymerization reaction pressure is an arbitrary pressure, and it is preferable to reduce the pressure as the reaction progresses. Alternatively, the raw material components may be dissolved in an inert organic solvent in which the raw materials can be dissolved and subjected to a heating polymerization reaction. In the polymerization reaction, the order of addition of each component used in the reaction may be arbitrary. As the polymerization catalyst, catalysts used in polyester polymerization reactions are preferably used, such as single substances or compounds such as sodium, potassium, calcium, magnesium, zinc, manganese, cobalt, titanium, tin, lead, antimony, germanium, etc., such as oxidation. Examples include organic and inorganic hydrochloric acids, hydrides, hydroxides, halides, alcoholates, phenolates, organic and inorganic hydrochloric acids, and double salts of rust salts.

The polymer thus obtained exhibits optical anisotropy when melted. In the present invention, this polymer is melt-spun using a paper spinneret having nozzle holes as shown in FIGS. 1 and 2, for example. 1 and 2 are partially enlarged longitudinal cross-sectional views of a spinneret in one embodiment of the present invention.

In FIGS. 1 and 2, 1 is an introduction part, 2 is an introduction hole, 3 is a land part, L is a land surface, L is a nozzle hole, and Q is a tapered corner. As shown in Figures 1 and 2, the spinneret used for melt spinning of the present invention has a land length L to peacock D ratio L/D of 5.
It is necessary that it is above.

When L/D is less than 5, the fibers obtained will not be highly oriented and will have high strength (more than Toshino d) and high Young's modulus (more than 3000 k9/skin 2), which are the objectives of the present invention, even if the taper angle Q is changed.
It is difficult to stably obtain high-performance fibers. Conventionally, the L/○ of the spindle used for melt spinning is at most 3.5.
Considering that the average value is usually 1.0 to 2.2, this was completely unexpected. Further, in the spinneret used in the method of the present invention, it is necessary that the angle Q of the taper connecting the land part and the introduction part 1 and the introduction part 2 or the land part 3 is 500 to 1300, preferably 600 to 1200. It is.

If the Boopa angle Q exceeds 130°, the flow of the molten polymer will be poor, making it difficult to orient the resulting fibers. On the other hand, 50o
If it is less than that, the Young's modulus of strength of the resulting fibers will decrease, although this may be due to too much shearing force being applied to the molten polymer. Effects of the Invention As described above, according to the method of the present invention, by using a specific polyester polymer, the land length of the nozzle hole during melt spinning,
By selecting a specific combination of pore diameter and taper angle, the above polymer can be stably melt-spun, and fibers with high strength and high Young's modulus can be obtained by only the yarn step.

The obtained fibers have excellent heat resistance and a strength of 7 g/
It exhibits excellent physical properties such as de and Young's modulus of 3000k9/side2 or more, and is particularly suitable for various reinforcing materials.
EXAMPLES The present invention will be specifically explained with reference to Examples below.
Ru.

In the examples, the intrinsic viscosity of the polymer was calculated from the value measured in a mixed solvent of phenol/trichlorophenol 50/50 (weight ratio). Example 1 70 mol% p-oxybenzoic acid residue, 30 mol% isophthaltaic acid residue
A polymer with an intrinsic viscosity of 2.1 (melt viscosity at 330oC of approximately 80,000 poise) consisting of 35 mol% of hydroquinone residues and 5 mol% of carbonate residues was discharged from a class thread nozzle with a discharge hole number of 1 at a weaving temperature of 330oC. Amount: 1g/rib, winding speed: 75h/m
Melt spinning was carried out to obtain a twill length of 12Me.

At this time, Table 1 shows the results of various changes in L, D, and Teher angle of the thread cap. If L/D is less than 5 or the taper angle is out of the range of 50o to 130o, not only will the strength or Young's modulus decrease (less than 7g nod, 3000k9/rib2), but in some cases, the winding may be difficult. I know that I won't be able to do it. Table 1

[Brief explanation of drawings]

1 and 2 are partially enlarged longitudinal cross-sectional views of a spinneret in one embodiment of the present invention. 1: introduction part, 2: introduction hole, 3: land part, L: land length, D: hole diameter, Q: taper corner. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A polyester polymer which is mainly composed of oxybenzoic acid residues, aromatic dihydroxy compound residues, and acidic acid groups and exhibits anisotropy when melted, is prepared by adjusting the land length L of the nozzle hole and the pore diameter. The ratio L/D with D is 5 or more and the taper angle is 50° ~
A method for producing high strength, high Young's modulus polyester fiber, which comprises melt spinning using a spinneret having an angle of 130°. 2. Claim 1, wherein the polyester polymer exhibiting anisotropy when melted is a polyester composed of oxybenzoic acid residues, aromatic dihydroxy compound residues, carbonic acid residues, and aromatic dicarboxylic acid residues. Manufacturing method described.